1. Field of the Invention
This invention relates to a projection display, more particularly to a light-source lamp unit used in a projector.
2. Description of the Related Art
Projection displays, such as liquid crystal projectors, are a well-known technique to project enlarged images of letters, figures and so on. Such a projection display uses a lamp unit that is a box case including a high-intensity lamp with a reflecting mirror (reflector) because the lamp in the projection display is required to produce a predetermined light output. A brief description will be made about the structure of a conventional lamp unit and a projector where the lamp unit is set.
FIGS. 14 and 15 illustrate the conventional projector: FIG. 14 is a perspective view of a lamp unit in schematic form; and FIG. 15 is a partially cut-out perspective view of a projector in which the lamp unit is attached.
As shown in FIG. 14, a lamp unit 1100 having a box case 1102 includes a high-intensity lamp 1104 with a reflecting mirror (reflector) 1103 is detachable from a projector body 1110. Such a detachable lamp unit is realized with a pin 1105 provided on the lamp unit 1100 and the corresponding plug 1116 provided in the body. There is no problem to put the pin 1105 in the body 1110 and the plug 1116 on the lamp unit 1100.
Attaching the lamp unit 1100 to the body 1110 couples the pin 1105 and the plug 1116. The plug 1 116 is electrically connected to a lighting circuit (not shown) provided in the body 1110. The lighting circuit starts/lights the lamp 1104 of the lamp unit 1100. There are a cooling fan 1117 and a cover 1111 behind and above the lamp unit 1100 attached in the body 1110, respectively.
In the body 1110, an optical system having the lamp as a light source and an image modulating means, which is used for controlling the optical system to display images and includes a liquid crystal panel and other components, are provided. Light emitted from the lamp 1104 passes through the optical system and projection lens 1114 and is projected onto a screen as an image.
By the way, many of the above-mentioned reflecting mirrors (reflector) 1103 are generally made of glass. The lamp, as discussed above, is attached to the body 1110 as a part of the lamp unit 1100. Because of this, replacement of the lamp involves replacement of the whole lamp unit 1100. An image display device in which an entire lamp unit is attached to the device body is disclosed in Japanese unexamined patent publication No. 2003-280096, for example.